1. Field of the Invention
The present invention relates generally to cap packages of Micro-Electro-Mechanical System (hereinafter referred to as “MEMS”) and more particularly, to a cap for use in a MEMS package.
2. Description of the Related Art
FIG. 1 is a schematic drawing showing a step of making a conventional MEMS package. After a substrate 10, which is basically defined on its top surface into a plurality of regions 13 on each of which a die 12 is bounded, is provided, a plurality of caps 14 are mounted on the substrate 10 one by one for protecting the dies 12 respectively. Thereafter, the substrate 10 thus obtained is cut along the gaps between the regions 13 into a plurality of MEMS package units each containing the die 12. In the step of mounting the caps 14 on the regions 13 of the substrate 10, conductive adhesive is used to mount the caps 14 one by one, resulting tin that the aforesaid mounting step is time-consuming. In addition, the gaps between the regions 13 shall be wider enough in order to be mounted with the cap 14 by adhesive, such that a lot of spaces are wasting.
To resolve the above-mentioned problems, an improved fabrication method of a MEMS package is developed as shown in FIG. 2. The substrate 20 is defined on the top surface thereof into several groups. Each group contains a plurality of regions 26 on each of which a die 24 is mounted. Thereafter, several caps 22, each of which has a plurality of accommodations 222 corresponding to the regions 26 respectively, are provided and mounted on the substrate 20. After completion of the cap mounting work, the caps 22 and the substrate 20 are simultaneously cut along the gaps between the regions 26 into a plurality of MEMS package units each containing the die 24 therein. Compared with the mounting work of the above-mentioned caps 14, the mounting work for the caps 22 is minimized. In addition, the gaps between regions 26 in a group can be reduced to an extent, such that more MEMS package units can be provided for the substrate 20 compared with the substrate 10 of FIG. 1 under a same area. However, since the cutting tool has to cut the bonded substrate 20 and cap 22 at a time in the cutting step, the cutting rate will be reduced and the cutting burrs will occur, such that a fine polishing work for removing the cutting burrs needs to be introduced after the cutting step, costing a lot of time.
In conclusion, it is desired to provide a new cap for use in a MEMS package, which can improve the disadvantages of the conventional caps 14 and 22 shown in FIGS. 1-2.